Defensive publication

ABSTRACT

PROCESS OF MAUNFACTURING A POLYESTER BY INITIALLY FORMING A MOLTEN PREPOLYMER FROM A GLYCOL, SUCH AS ETHYLENE GLYCOL AND A DIFUNCTIONAL COMPOUND SUCH AS TEREPHTHALIC ACID OR A LOWER DIALKYL DIESTER THEREOF, SOLIDIFYING THE RESULTING PREPOLYMER, CRYSTALLIZING THE PREPOLYMER, PULVERIZING THE CRYSTALLIZED PREPOLYMER, POLYMERIZING THE PULVERIZED PREPOLYMER IN A HEATED FLUIDIZED BED IN THE PRESENCE OF A CONTINUOUSLY INTRODUCED STREAM OF PREHEATED INERT GAS, WHEREIN AN IMPROVEMENT RESIDES IN MAINTAINING WITHIN THE FLUIDIZED BED A CONTROLLED CONCENTRATION OF GLYCOL VAPOR, WHEREBY THE MOLECULAR WEIGHT OF THE POLYMER IS CAUSED TO ATTAIN A PREDETERMINED VALUE.

DEFENSIVE PUBLlCATlUN UNITED STATES PATENT OFFICE Published at therequest of the applicant or owner in accordance with the Notice of Dec.16, 1969, 869 0.G. 687. The abstracts of Defensive Publicationapplications are identified by distinctly numbered series and arearranged chronologically. The heading of each abstract indicates thenumber of pages of specification, including claims and sheets ofdrawings contained in the application as originally filed. The files ofthese applications are available to the public for inspection andreproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to themerits of alleged invention. The Patent Oflice makes no assertion as tothe novelty of the disclosed subject matter.

PUBLISHED JUNE 1, 1971 T887,005 CONTROL OF MOLECULAR WEIGHT 0F POLY(ETHYLENE TEREPHTHALATE) DURING SOLID PHASE POLYCONDENSATION Charles J.Kibler, 620 Dogwood Drive 37663; David L. Nealy, 908 Afton St. 37660;and Thomas G. Davis, 1368 Garden Drive, 37664, all of Kingsport, Tenn.

Filed Apr. 2, 1970, Ser. No. 25,270 Int. Cl. C08g 17/03 US. Cl. 260-75No Drawing. 15 Pages Specification Process of manufacturing a polyesterby initially forming a molten prepolymer from a glycol, such as ethyleneglycol and a difunctional compound such as terephthalic acid or a lowerdialkyl diester thereof, solidifying the resulting prepolymer,crystallizing the prepolymer, pulverizing the crystallized prepolyrner,polymerizing the pulverized prepolyrner in a heated fluidized bed in thepresence of a continuously introduced stream of preheated inert gas,wherein an improvement resides in maintaining within the fluidized bed acontrolled concentration of glycol vapor, whereby the molecular Weightof the polymer is caused to attain a predetermined value.

